As a participating institution in the Primary Breast Cancer Therapy Group, (NSABP), we are contributing data from patients entered into Protocol No. 4 of the group, which is a protocol to evaluate the relative efficacy of radical mastectomy, total mastectomy with radiation and total mastectomy alone in patients with clinically negative axillary nodes. A comparison between radial mastectomy and total mastectomy with radiation is made in those with positive axillary nodes. The date, over 900 patients have been entered into the protocol by 35 institutions of which ours is one. The present study so as to bring it to completion and to permit participation in the development and implementation of new protocols which are to follow. It is premature to make statements relative to the various treatment modalities. Interesting data has, however, been obtained relative to auxillary material being collected. It has been demonstrated that patients randomized into various treatment categories are similar according to a variety of criteria. Moreover, information has been accumulated relative to the pathology of breast cancer. The submittal of data has been satisfactory. If patient accrual continues at the present rate, it should be adequate to complete the study (accrual) within the next year.